Heat regenerator of the chimney type



Patented Aug. 23, 1949 UNITE STAT'ES e -MEM FFICE HEAT REGENEBATOR OF THE( CHIMNEY TYPE; e

li Claims. 1

This invention relates to a heat regenerator, of the chimney type, particularly adapted for use in connection with a steel-making, regenerative, open-hearth furnace. The object of the inven tion is to get more heat returned to the furnace and a more uniform hearth temperature resulting in a greater rate of production without increase in rate of fuel supplied, At the same time, it provides a Construction permitting the use of a dust blowing tool inside the regenerator.

A specific example of the invention is illustrated by the accompanying drawings in which:

' Figura 1 is a horizontal section taken on the line I-I in Figure 2; `figure 2 is a Vertical section taken on the lin II--II in Figura 1;

Figure 3 is a View taken on the line III III in Figure 2 showing the wall of the regenerator chamber at its stack end;

Figure 4 is a full depth cross-section taken on the line IV-IV in Figure 2 looking toward` th e hearth end. of the regenerator;

Figura 5 is a plan View of a special brick;

Figure 6 is a sectional View taken on the line VI-VI of Figures 5 and. 8;

Figure 7 is a View showing a modified' manner of applying the special bricks to the top ot the regenerator;

Figure 8 is a plan View of a modification of the special brick shown in Figures 5 and.: 6 When the invention is applied to other forms of regenerators.

Figure 1 shows the top View, of the chimne-ys while Figure 2 shows that they are arrangecl in three vertically separated sections marked: 2, 3 and i. Between these regenerator sections are the separators l shown in Figure 4. These Sep.- arators 'i run lengthwise of the regeneratorand are in alignment with the walls `between thechimney passages running lengthwse of the. regenerator. rows of horizontal passages i across the regenerator as shown in Figures 2 and 4. These horizontal passages E are connected to corresponding openings 9 in the stack end wall of the regenerator chamber as shown in Figures 2 and 3. Also above the regenerator top are the dust blowing holes i& in the same staok enti wall. in Figures 2 and. 3, the entire regenerator is supported by the supporting walls e which are in alignment with the chimney passage walls run ning lengthwise of the regenerator. V Between the suporting walls 8 are the underneath passages 5 that connect to the steel: and air or juel inet .5. amg

This arrangement also gives two:

As shown val-ves. Aboye the regenerator is the passage l connecting the regenerator with the hearth.

As seen in Figure 2 the cross-sectioned Walls of the, chimney passages for two adjacent regenerater sections are staggered to each other in the, direction running lengthwise of the regenerator.

The crossr sectioned walls of the chirnney passags decrease in bluntness on their top ends in the direction oi the hearth for all three regenerator sections 2, 3 and i) This is shown hy lorie-ks il, !2 and !3 in both Figures 1 and 2. on theloottom encls of these Walls,`the bluntness cle-` creases in the direction of the stack end. In other words the transverse areas of the top of the chimney passages is greatest at the hearth end where the fine gases enter the regenerator and the least at the stuck end of the regenerator. 'rhe transverse areas of the bottom of the chimney passages is greatest at the steel; end where the, air' or tuel gas enter the regenerator and least at the hearth end.. The above is true of all three regenerator sections 2, 3 and 4.

Thefregenerator is of the basket weave construction as plainly shown in the vicinity of the? stack end of the regenerator in Figures 1 and 2 and is mostly made up of coinmon flat bricks ll alsoshown in Figures 1 and 2. The special bricks 1 2, which are used at the top and bottom ofeach regcnerator section are shown in Figures 5 and 6. The brick liz has a flat central part T on the tapered edge which bears on the tops and bottoms of the separators i as well as the tops of supporting walls. 8 as shown in Figure 4. The special bricks, 13 are thesame as bricks !z except that they are of a longer teper and. the dimension R in' Figures 5 and 6 is less. The special bricks IZ and l3 'are of a form that is adaptahle to the basket weaye Construction When used at the top and bottom of a regenerator section.

If a more fiared opening of the chimney passages at the, top. of the regeneratcr is required then the laying of the special bricks !Z and 1.3 would appear inFigure 1 as shown in Figure '7.

In operation the, waste gases come from the t hearthalcng thep-assage i above theregenerator;

then down through the regenerator to the. passages 5 and ont to the stack. W hen the waste gas flow in the furnace is reversed air comes in through passage 5, and up, through the regenerator and out to the hearth through passage I. When the regenerator is applied to preheating fui gas the same cycle occurs as in air preheating.

In the ordinary straight chimney type of reenerat he w j t easv pc y arri n ss.

qi a e case e the. Stath mi oi t passage above the regenerator, which causes more downward flow in the stack end of the regenerator than at its hearth end. Similarly the incoming air velocity causes more upward flow at the hearth end of the regenerator than at its stack end.

Looking at Figure 2 it will be seen that the downward flow of the waste gases meet the blunt tops of bricks ll at the stack end, while this downward flow meets the tapered tops of bricks !3 at the hearth end of the regenerator for all three sections 2, 3 and 4. Since the incoming air or fuel gas flow is in the reverse direction to that of the incoming waste gas flow, the bottoms of the' three regenerator sections show blunt wall ends at the hearth end and tapered wall ends at the stack end of the regenerator. The bricks z are intermediate in efect between bricks l i and !3 on the fluid flow. Since bluntness obstructs flow more than tapering, it is plain that the distributions of both the downward and upward flows within the regenerator are much improved.

The tapering of the bricks on top of each regenerator section in the vicinity of the hearth end decreases the deposit of dirt from the waste gases on top of the regenerator sections and in the chimney passages since the falling dirt tends to slide down the sloping suriaces. This condition takes care of the excess fall of dirt at the hearth end of the regenerator.

The horizontal passages 6 should not be deeper than that which allows the regenerator to work properly with a moderate deposit of dirt within them. This condition makes the blunt ends of bricks li more efiective within the regenerator because of sharper turn losses across passages 6.

Internal dust blowing is done through the hoies 9 in the stack end wall and along passages E within the regenerator. The dust blowing tool consists of a pipe having a short right angle bend on the end within the regenerator. By using steam or air supplied to the pipe under pressure the blowing may be done up and down the chimney passages as well as on the tops of the wall ends in the passages 6.

The staggering of the chimney passages of two adjacent regenerator sections improves the heat transfer rate by causing turbulence and also by splitting of the flow to obtain a greater temperature difference between the flow and the chimney walls for both waste gases and air.

If the lower row of passages are below the floor line then there will be no corresponding openings 9. The internal dust blowing for regenerator section 4 can be done from the top row of passages 5 To make the blowing fully effective it may be necessary to use only the spe cial bricks !3 on top of regenerator section i.

Brick 20 shown in Figures 6 and 8 is a modification of brick !2. In this embodiment the bearing surfaces T' and T' replace the single hearing surface T for the purpose of applying the invention to the form of regenerator that is made by placing bricks end to end so as to form rows alternately lengthwise and crosswise of the regenerator and give straight Vertical passages. This regenerator can also be divided vertically into sections by horizontal passages between them and the vertical passages staggered as shown in Figure 2.

The invention may be applied to other forms of Construction other than the basket weave The main features are variable flaring on at least one end of the upright passages and also staggering of regenerator sections as shown in Figure 2.

The invention is applicable to regenerator sections that have their vertical gas passages or chimneys either long or short.

In the following claims the word "side" means either top side or bottom side.

I claim:

1. A heat regenerator having a plurality of sections arranged vertically one above the other, each of said sections having substantially vertical gas passages therein arranged in substantially longitudinal rows, the gas passages of a first section being off-set with respect to the gas passages of an adjacent second section so that the walls of the second section split the flow of gas from the first section to the second section, each of the gas passages of the first section being of substantially uniform transverse area for the greatest part of its length, the ends of the last named gas passages adjacent the second section increasing in transverse area from end to end of said longitudinal rows.

2. A heat regenerator according to claim 1 in which the variation in transverse area is provided by flaring the ends of the passages to make them wider in the dimension parallel to the longitudinal rows.

3. A heat regenerator of the chimney type having a plurality of sections arranged vertically one above the other, each of said sections having substantially vertical chimneys therein for the passage of gas, said chimneys being arranged in substantially parallel longitudinal rows, the exits of a first section being off-set from the inlets of an adjacent second section so that the walls between the chimney passages in each of the said rows split the gaseous flow from one to the other of the said two sections, the chimney passages being of substantially uniform transverse area for the greatest part of their length, the ends of the chimney passages at said exits increasing in transverse area and the ends of the chimney passages at said inlets decreasing in transverse area from one end of said longitudinal rows.

4. A heat regenerator according to claim 3 having rows of horizontal longitudinal passages between the two sections, the walls of said horizontal passages being in the same plane as the walls of the longitudinal rows of chimney passages.

5. A heat regenerator according to the claim 4 in which the ends of the chimney passages on the entrance side of the regenerator decrease in transverse area from the gas entry port.

6. A heat regenerator according to claim 5 in which the variation in cross-section of the chimney passages on the said side of the regenerator is provided by special bricks each having a rectangular transverse section extending a distance on each side of the center line thereof, thereby providing a, central flat upper surface, a flat portion on each side of the central flat surface extending to the ends of the brick, and a downwardly tapering portion on each side of each flat portion extending for the full length thereof to the adjacent longitudinal side of the brick.

7. A heat regenerator having upright chimney gas passages of substantially uniform transverse area for the greatest part of their length, the ends of the chimney passages on at least one side of the regenerator having difierent transverse areas, the transverse area of said ends being greatest at the gas entry port and decreasing in the passages further removed from the said gas entry port.

8. A heat regenerator according to claim 7 in which the variation in transverse area is provided by flaring the ends of the passages.

9. A heat regenerator having upright chimney passages, the intermediate portions of said passages having uniform transverse areas, said passages being arranged in longitudinal rows, gas passages at the top and bottom of said ch'mney flues, the ends of the chimney passages at the top of said regenerator decreasing in transverse area from the top gas port and the ends of the chimney passages at the bottom of said regenerator decreasing in transverse area from the bottom gas port.

10. A heat regenerator according to claim 9 in which the variation in transverse area is provided by fiaring the passages.

11. A heat regenerator according to claim 3 having rows of horizontal longitudinal passages between the two sections, the walls of said horizontal passages being in the same plane as the walls of the longitudinal rows of chimney passages, the ends of the chimney passages on the REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 252,909 Swindell Jan. 31, 1882 274357 McKenna Mar. 20, 1883 292,188 We'mer Jan. 22, 1884 20 1,686,826 Loftus Oct. 9, 1928 1,980,827 Reed Nov. 13, 1934 

